Speed-reducing gear for aviation-engines.



A. IVIAIRE.

SPEED REDUCING GEAR FOR AVIATION ENGINES.

2 SHEETS-SHEET I.

Patent ad "A 23, 191%.

APPLICATION FILED AUG.9, 19H.

A. MAIRE.

SPEED REDUCING GEAR FOR AV |ATION ENGINES.

APPLlCATlON FILED was. 1911.

' Pimilltfid Apr. 23, 1918.

2 SHEETS-SHEET 2.

H l GENTEUIIJ, FRANCE, ASSIGNOR T0 SOCIJETE LOBRAHIJE DES l ETLISSEMENTSIIDE DIETRICH & CIE. DE LUNEVILJLE, 01E PIS, FIR.

SPF-REDUCING GEAR FOR AVIATION-ENGINES.

Specification of Letters Patent.

Application tiled August 9, 1917. Serial Ito. 185,241.

Oise, in the Republic of France, have invented new and usefulImprovements in Speed-Reducing Gears for Aviation-Engines, of which thefollowing is a specification.

For the purpose of providing a very powerful engine of relatively smallweight, it is generally necessary that the s eed of revoluthat of theengine crank sha t shall be very On the other hand it has been foundthatscrew propellers have a better efficiency when they run at a lowspeed, which allows of making them of very large diameter and very greatwidth.

The present invention has now for its object to provide an improvedspeed-reducing gear for driving a screw propeller from an aviationengine at a suitable speed. This speed multiplying gear allows ofretaining the center of the propeller in the main axis of the engine andof distributing the transmitted power over a very large number ofteethin the case oftoothed wheels. The improved gear eonsists of aplanetary driving system centered on the engine main shaft. Thepropeller hub is driven by the sleeve of the speed-reducing gear bymeans of flutes or grooves, and" the fixin of the said gear is assuredby a nut provi ed with an internally toothed brake, whereby the systemcan be easily dismounted.

One practical form of the improved apparatus is illustrated by way ofexample in the accompanyin drawings in which Figure 1 is a hongitudinalsection of the improved apparatus.

Fig. 2 is a cross section thereof.

Fig.3 is a cross section showing the man- I ner in which the propellerhub is driven by the sleeve of the speed-reducing gear.

Fig. 4 is a front view of the nut with brake teeth.

As shown, the improved speed-reducing gear is constructed as follows:

Un the end of the crank-shaft, A, there is mounted a pinion B which iskeyed u on the shaft. U11 this pinion there is fine a ball M r t) whichto a double the a and which is fixed in place by means of a sleeve Dtightened up by a nut E.

The ball bearing or stop serves to center the hub of the propellersleeve F which is centered on the other hand by the gun metal ring G.The propeller sleeve F is driven.

' fill by the following means:

Patented Apr, an, ap I It is-formed at H with enlargements that allow ofsupporting the shafts on which the pinions are mounted. These pmionsengage on one hand with a toothed ring J .fixed to the gear case orcrank chamber,

which is consequently fixed, while they engage on the other hand withthe pinion B.

The arrangement constitutes a planetary system, and the reduction inspeed of the propeller sleeve F relatively to the crank shaft isdetermined by the number of teeth in the'fixed toothed ring and in thedriving pinions. a

In order to diminish. the strain on the teeth that serve for driving, itis sufiicient to provide asuficient number of pinions. In Fig. 2 thesystem is shown as comprising four pinions. y

The propeller is provided with a false hub K. i The driving of thepropeller by the speedreducing gear is efi'ected by mean of a series ofteeth formed on one hand on t e sleeve F and on the'other hand on thefalse hub K, which teeth serve to distribute over a very large surfacethe power that is required for driving (Fi 3).

()n the ot er hand for the purpose of assuring a good centering of thepropeller on the speed-reducing gear, a conical part is provided on therear portion of the sleeve, while the false hub is centered in front ona cylindrical part. The fixing of the propeller on the false hub iseffected by means of a nut L which is capable of turning relatively tothe false hub, and forms as it were one piece with the latter as regardslongitudinal motion. For this purpose the nut is formed with a segment Mthat serves to drive it for the purpose of unscrewing, while 1n thescrewing movement the hub is tightened against the conical part N.-

In order to prevent the nut L from unscrewing during working, thespeed-reduc as it were one til.

act

piece with the said sleeve as regards rotary motion. 'A sprinaP has aconstant tendency to force the cap in the outward direction. The cap isformed with'teeth of very fine pitch, and the nut is formed with similarteeth adapted to engage with the teeth .of the .cap 0 (Fig. 4).

When the fixing of the propeller is assured, the cap 0 is allowed toreturn by giving if necessary a small additional tightening movement inorder that the cap 0 shall engage with its cooperating part.

From-this moment onward the whole system forms as it were one piece withthe propeller sleeve, and the nut is eventually locked in place.

Lubrication of the speed-reducing gear is assured by oil under pressuresupplied from the interior of the shaft, this oil passing crank chamberor through the passage Q, into the grooveR whence it effects thelubrication of the cap of the sleeve.

The oil after having lubricated the said cap, passes through the ballbearing C, and

thence passes by centrifugal action to the axles-of the satellitepinions; it lubricates the friction rings and thence escapes to theperiphery where it lubricates the fixed teeth and consequently also theteeth of the satellite pinions. Any oil in excess returns to the gearcasing whence it is drawn by the pump,

S is the casing fixed to the stationary toothed ring J for the purposeof preventing leakage of oil to the outside.

This casing S is bored. The ropeller sleeve is rovided with teeth ofsuitable direction w ich revolve with slight friction in the casing S,.in such a manner that the oil which would have a tendency to flow awayalong the casing toward the outside, is thrown back into the interiorby. the reaction of the teeth.

It is to be understood that the crank shaft may be held in a fixedposition in the lon- .gitudinal direction; in the example shown thisconnection is effected by means of a double ball bearing. c Having nowdescribed my invention, what I clalm as new and desire to secure by 'Letters Patent is:

1. A speed-reducing gear for aviation engines comprising in combination:a driving shaft, a driving pinion fixed on the end'of saiddriving'shaft, a fixed toothed provided with internal teeth, centered onthe driving shaft and arranged around the said pinion, a loose sleevearranged around the driving shaft, means for centering said sleeve onthe driving shaft, satellite pinions carried by the said sleeve andgearing on one hand withthe drivin opinion and on .the

other hand with the xed toothed ring; a,

naespse screw propeller, a false hub fixed to the said propeller andarranged around the said sleeve, means for enabling the sleeve to drivethe false hub; means for centering the false hub on the sleeve and meansfor fixing the false hub, on the sleeve, substantial] as described andfor the purpose set fort tering this sleeve on the driving shaft, a

screw. propeller, a false hub fixed to the said propeller, arrangedaround the said sleeve surface, means for centering the false hub on thesleeve, and means for fixing the false hub on the sleeve, substantiallyas described and for the purpose set forth.

3. A speed reducing gear for aviation engines comprising in combination:a driving shaft, a driving pinion and integral therewith a sleeve, fixedon the end of said driving shaft, a fixed toothed ring provided withinternal teeth, centered on the driving shaft and arranged around thesaid pinion; a

loose sleeve arranged around the driving shaft and provided with teethformed on its and provided with teeth formed on its inner outer surface,satellite pinions carried by the said loose sleeve and gearing on onehand with the driving pinion and on the other hand with the fixedtoothed ring, a gun metal ring carried by the loose sleeve, a ballbearing interposed between the said loose sleeve, and the sleeve of thedriving pinion, a cap fixing this ball bearing a nut tightening thiscap, a screw pro eller, a false hub fixed to the said prope ler, arraned around the sleeve which carries the slate lite pinions, saidfalse'hub and loose sleeve having conical and cylindrical sure facesprovided with teeth formed. on their inner surfaces, a nutfixing thefalse hub to the sleeve, and a nut brake rovided on this nut,substantially as descri ed and for the purpose set forth.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

AUGUSTE MAIRE. Witnesses:

LOUIS Mosns, Clams. P. Present.

